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In this research, mango parts (kernel and integument) were loaded into a polylactic acid (PLA) matrix by a casting process to develop biocomposite materials. These materials should present improved mechanical and thermal properties and have the potential to be used as environmentally friendly, biodegradable food packaging material with extended shelf life. For this purpose, the research was divided into two parts: step 1, ground materials of a certain particle size from a previous work1 and step 2, which are the materials from Step 1 ground again. The samples were characterized by x‐ray diffraction, scanning electron microscopy (SEM), laser granulometry, texture tests, and thermal analysis. The difference between them was particle size distribution, impacting the materials' mechanical strength and degradation rate. Three biocomposites were made (PLA/kernel, PLA/integument, and PLA/kernel/integument) in both steps. SEM was used to observe the size distribution of the mango seed and sample morphology. In addition, resistance values increased with the addition of kernel or integument particles. Biocomposite biodegradability was also evaluated. Based on the results of this study, the biocomposites showed high mechanical properties and thermal stability, making them suitable for applications such as food packaging and structural components to help reduce environmental loads and microplastic generation. [ABSTRACT FROM AUTHOR]

This work focuses on the characterization of five palygorskite clays from the Brazilian state of Piaui and their feasibility as eco-friendly adsorbents for the removal of Fe3+ ions from aqueous solutions. For characterization, we applied the techniques of X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), size distribution measurements, density measurement by He pycnometry, superconducting quantum interference device (SQUID) magnetometry, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA/DTA), zeta potential measurement, hydrophobicity determination by contact angle, Brunauer–Emmett–Teller surface area analysis (BET technique) and atomic force microscopy (AFM). Batch experiments were performed in function of process parameters such as contact time and initial concentration of Fe3+. The natural palygorskites (Palys) had excellent performance for the removal of Fe3+ from aqueous solutions by adsorption (around 60 mg/g), and the Langmuir is supposedly the best model fitted the experimental data. [ABSTRACT FROM AUTHOR]

Geopolymers are a type of inorganic polymer that typically have a monochromatic appearance. This study investigates the formation of artificial chrysocolla by immersing these materials in Cu(II) ion solutions. The resulting synthetic chrysocolla possesses magnetic properties and characteristic silicate bands in its structure, indicating geopolymerization and a similarity to natural chrysocolla. Furthermore, the inclusion of copper and zinc ferrites in the nano-modified geopolymer matrix enhances its properties and potential antiviral properties. The antiviral test results show that synthetic chrysocolla based on nano-modified geopolymers has a mild antimicrobial effect. However, more testing is needed to determine its effectiveness against bacteriophage, as bacterial growth was observed in the area where the nano-modified geopolymer bacteriophage blend was applied. In addition to its potential antiviral properties, synthetic chrysocolla's porous structure allows it to act as an adsorbent, making it useful in the development of antiviral filters. Artificial chrysocolla can be obtained through a geopolymeric matrix by immersing it in a solution of Cu(II) ions, which can occur by ion exchange of the ions present in the aluminosilicate structure with Cu(II). Neutralization of the geopolymer matrix by washing with distilled water is required prior to immersion to ensure proper formation of chrysocolla and not copper(II) hydroxide on the geopolymer surface. Overall, this study provides evidence for the successful preparation of nano-modified synthetic chrysocolla from geopolymers and ferrites, with properties and chemical composition similar to those of natural chrysocolla. The presence of copper ions in its composition and the incorporation of copper and zinc ferrites can contribute to its use as a resource to combat viral pathogens. [ABSTRACT FROM AUTHOR]

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The effects of concentration and surface modification of two Brazilian bentonite clays on nanocomposites' properties based on polylactic acid – (PLA) were investigated. The samples were prepared by the extrusion/injection method to obtain biodegradable packaging plastics. The raw materials and their bionanocomposites were characterized by various techniques. Natural clay samples presented a size of around 2 μm while the modified ones' size was 5–6 μm, probably due to the presence of cetyltrimethylammonium bromide in the interlayer space. The particle size and the contact angle increased with the treatment and the clay's density decreased. The organoclays were homogeneously dispersed in PLA, which can be associated with the interactions between PLA chains' carbonyl groups and the organoclays. The bionanocomposites present modified clay particles axis aligned to the flow direction of the extruder/injector. Chocolate organoclay acts as a nucleating agent to PLA crystal growth, increasing the sample's crystallinity, while Bofe organoclay interferes with the amorphous chain's mobility and diminishes the sample's crystallization. The addition of both organoclays to PLA diminished the sample's elongation at break and strength, although the organoclays increased the sample's Young modulus, even though Bofe organoclay is more active in PLA amorphous phase and Chocolate organoclay on the crystalline one. [ABSTRACT FROM AUTHOR]